CVE-2026-80775Hinoki check available

Kernel use-after-free via unlocked futex counter allocation

Published Sep 4, 2026 · Updated Sep 4, 2026

A race condition in the Linux kernel 6.17 futex subsystem allows local users to trigger a use-after-free through nested vfork calls. During concurrent PR_FUTEX_HASH_SET_SLOTS calls, futex_hash_allocate() overwrites an unlocked mm->futex.phash.ref allocation, losing the first counter and freeing a referenced private hash. A nested vfork child must be killed with SIGKILL so its parent and grandchild run in one mm; futex_q_lock() then writes to freed kernel memory.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

A race condition in the Linux kernel 6.17 futex subsystem allows local users to trigger a use-after-free through nested vfork calls. During concurrent PR_FUTEX_HASH_SET_SLOTS calls, futex_hash_allocate() overwrites an unlocked mm->futex.phash.ref allocation, losing the first counter and freeing a referenced private hash. A nested vfork child must be killed with SIGKILL so its parent and grandchild run in one mm; futex_q_lock() then writes to freed kernel memory.

The record

CVE
CVE-2026-80775
Published
Sep 4, 2026
Updated
Sep 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, CWE-416
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.17
  2. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <86d12b34bafc9a4c271a9edefea88855a934d6e5
  3. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <bde0238083647381d4747355c5a19115a3422b96
  4. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <c4b4972d8edcdf50b6518f55119e129d2f668a10
  5. Affected versionversion=d9b05321e21e4b218de4ce8a590bf375f58b6346 <ff252ed45c8263525f2f54d81c5fa6d547fba344

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.17; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <86d12b34bafc9a4c271a9edefea88855a934d6e5; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <bde0238083647381d4747355c5a19115a3422b96; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <c4b4972d8edcdf50b6518f55119e129d2f668a10; version=d9b05321e21e4b218de4ce8a590bf375f58b6346 <ff252ed45c8263525f2f54d81c5fa6d547fba344

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo